Current work-in-progress crbug.com/567021

third_party/WebKit/Source/core/dom/ShadowTreeStyleSheetCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
@@ skipping 10 matching lines @@
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/dom/ShadowTreeStyleSheetCollection.h"
 
 #include "core/HTMLNames.h"
 #include "core/css/CSSStyleSheet.h"
+#include "core/css/StyleSheetContents.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/Element.h"
 #include "core/dom/StyleChangeReason.h"
 #include "core/dom/StyleEngine.h"
 #include "core/dom/StyleSheetCandidate.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/html/HTMLStyleElement.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 ShadowTreeStyleSheetCollection::ShadowTreeStyleSheetCollection(ShadowRoot& shadowRoot)
     : TreeScopeStyleSheetCollection(shadowRoot)
 {
 }
 
-void ShadowTreeStyleSheetCollection::collectStyleSheets(StyleEngine& engine, StyleSheetCollection& collection)
+void ShadowTreeStyleSheetCollection::collectStyleSheets(StyleSheetCollection& collection)
 {
     for (Node* n : m_styleSheetCandidateNodes) {
         StyleSheetCandidate candidate(*n);
         DCHECK(!candidate.isXSL());
 
         if (!candidate.isCSSStyle())
             continue;
 
         StyleSheet* sheet = candidate.sheet();
         if (!sheet)
             continue;
 
         collection.appendSheetForList(sheet);
-        if (candidate.canBeActivated(nullAtom))
-            collection.appendActiveStyleSheet(toCSSStyleSheet(sheet));
+        if (candidate.canBeActivated(nullAtom)) {
+            CSSStyleSheet* cssSheet = toCSSStyleSheet(sheet);
+            collection.appendActiveStyleSheet(std::make_pair(cssSheet, &document().styleEngine().ensureRuleSetForSheet(*cssSheet)));
+        }
     }
 }
 
-void ShadowTreeStyleSheetCollection::updateActiveStyleSheets(StyleEngine& engine, StyleResolverUpdateMode updateMode)
+void ShadowTreeStyleSheetCollection::updateActiveStyleSheets()
 {
     StyleSheetCollection collection;
-    collectStyleSheets(engine, collection);
-
-    StyleSheetChange change;
-    analyzeStyleSheetChange(updateMode, collection, change);
-
-    if (StyleResolver* styleResolver = engine.resolver()) {
-        if (change.styleResolverUpdateType != Additive) {
-            // We should not destroy StyleResolver when we find any stylesheet update in a shadow tree.
-            // In this case, we will reset rulesets created from style elements in the shadow tree.
-            styleResolver->resetAuthorStyle(treeScope());
-            styleResolver->removePendingAuthorStyleSheets(m_activeAuthorStyleSheets);
-            styleResolver->lazyAppendAuthorStyleSheets(0, collection.activeAuthorStyleSheets());
-        } else {
-            styleResolver->lazyAppendAuthorStyleSheets(m_activeAuthorStyleSheets.size(), collection.activeAuthorStyleSheets());
-        }
-    }
-    if (change.requiresFullStyleRecalc)
-        toShadowRoot(treeScope().rootNode()).host().setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::ActiveStylesheetsUpdate));
-
-    collection.swap(*this);
+    collectStyleSheets(collection);
+    applyActiveStyleSheetChanges(collection);
 }
 
 } // namespace blink